MACHINE AND METHOD FOR APPLYING STAMPS TO CONTAINERS

Technical field

This invention relates to a machine and a method for applying stamps to containers, in particular, rigid or semi-rigid containers. More specifically, in the context of this invention, the containers may be metallic (tins or cans) or made from plastic or cardboard, and may have different shapes (cylindrical, parallelepiped, generically prismatic or other shapes) or may even be bags or pouches.

A typical application of the invention is for applying stamps to containers for snus. It is, however, also applicable to containers for: electronic cigarette components, filter segments and/or rolling papers for "roll-your-own" cigarettes, cigarette packets (cartons) and others still.

The term "stamp" is used to mean a small piece of material, usually paper, rectangular in shape and affixed to the outside of a container of products subject to a government tax in such a way that it lies across a line along which the container is opened. Thus, the stamp constitutes a tamper evident seal and is irreversibly damaged or torn when the container is opened for the first time.

Background art

Prior art machines for applying stamps are equipped with a conveyor which transports the containers along a feed direction through a stand-alone applicator device configured to apply one stamp to each container in sequence.

Machines like those described above have the inherent drawback of being intended for processing only one specific type of container of one specific size and/or only one specific type of stamp of one specific size; thus, to change over to a container and/or a stamp of a different size and/or type, it is necessary to replace the stand-alone applicator device with a different device optimized for the new container and/or stamp size or type.

This changeover is thus very complex, costly and time consuming.

Aim of the invention

In this context, the aim of this invention is to provide a machine and method for applying stamps to containers and which has a high flexibility of use and which, in particular, allows changeover to be carried out quickly and easily. The technical purpose and aim specified are substantially achieved by a machine and a method for applying stamps to containers, comprising the technical features described in claims 1 and 13 and/or in one or more of the accompanying claims.

Brief description of the drawings

Further features and advantages of this invention are more apparent in the detailed description below, with reference to a preferred, non-limiting embodiment of a machine and a method for applying stamps to containers, as illustrated in the accompanying drawings, in which:

Figure 1 shows a perspective view of a machine and a method for applying stamps to containers according to this invention;

Figure 1 A shows an enlarged detail from the view of Figure 1 ;

Figure 2 shows a perspective view of the machine of Figure 1 from a different angle;

Figure 2A shows an enlarged detail from the view of Figure 3;

Figure 3 shows a detail of the infeed station of the machine according to the invention;

Figure 4 shows a detail of an intermediate device of the machine according to the invention;

Figure 5 shows a detail of the outfeed station of the machine according to the invention;

Figure 6 shows a detail of the outfeed station of Figure 5;

Figures 7 and 8 show cross sectional views of an orienting device used in the machine according to the invention, in two distinct operating steps;

Figures 9A-9F show a sequence of operating steps performed by an applicator device used in the machine according to the invention;

Figures 10 and 1 1 show a cross sectional view of the machine according to a different embodiment of the invention and in two different operating steps.

Detailed description of preferred embodiments of the invention

The numeral 1 in the accompanying drawings denotes in its entirety a machine for applying stamps B to a container C.

In the embodiment illustrated, the containers C are disc-shaped or cylindrical, that is to say, they have a circular base and a predetermined height, depending on their contents, which may, for example, be snus. The containers C may thus be made from aluminium or plastic and may comprise two half-shells that fit together along a circular connecting line.

The invention is, however, equally applicable to containers of any size or structure: for example, axisymmetric containers or parallelepiped shaped containers or, more generally speaking, containers having a polygonal base (prismatic containers, for example, having a hexagonal or octagonal base), preferably having a succession of lateral faces recurring all the way around them to define a regular distribution of identical faces.

The stamps B are defined by small sheets of material, preferably paper, having an elongated shape, in particular rectangular, and, in the case of revenue stamps, bearing government markings.

The machine 1 comprises a conveyor 100 having a feed direction A and configured for transporting a succession of containers C intermittently along the feed direction A.

The conveyor 100 illustrated is in the form of an endless cleated conveyor, that is to say, provided with a succession of containing spaces, each intended to accommodate a respective container C according to a specific orientation. The conveyor 100 is configured to dispose the containers C, which have a circular based structure, each with its main axis (in this case, defining the axis of symmetry) parallel to the feed direction A.

In different embodiments, however, the conveyor 100 may have any structure, for example, it may be a belt conveyor, an articulated mesh conveyor or other suitable type of conveyor.

In addition, the conveyor 100 may dispose the containers C in such a way that the main axis of each (that is, an axis perpendicular to the supporting base of the container) has a different orientation, in particular, perpendicular to the feed direction A, hence oriented laterally or vertically.

The conveyor 100 extends between an infeed station 2, where it receives a succession of containers C from a feed line, and an outfeed station 3, where the containers C are fed out and which is described below.

Disposed along the conveyor 100 are an orienting device 200 (optional) and an applicator device 300, which are disposed, in particular, on the upper section of the conveyor 100.

The orienting device 200, disposed upstream of the applicator device 300, is configured to rotate the container C about an orienting axis X, preferably parallel to the feed direction A. For this purpose, the orienting device 200 comprises disengagement means 210, configured to temporarily disengage each container C from the conveyor 100, and orienting means 220 operating on the container C disengaged from the conveyor 100 to rotate the container C about the orienting axis X.

The disengagement means 210 comprise a lift 21 1 , provided with a rotatable support 212 for supporting the bottom of the container (C) so that the container C can rotate about the orienting axis X. The rotatable support 212 is preferably made in the form of a roller or pair of rollers, in particular having axis of rotation parallel to the orienting axis X. In the case illustrated, where there is a single roller, it is also preferable for there to be, on both sides of the conveyor 100, and in particular, on both sides of the container C to be lifted, a guiding member 213, in particular an additional roller, configured to define a support for the container C while it is being lifted.

The lift 21 1 may be made in the form of a rocker or lever having the rotatable support 212 at one end, and rocking between an inactive position (Figure 8), where it is clear of the conveyor 100 (in particular, under it) and a lifting position (Figure 7) where it comes into contact with an underside portion of the container C and lifts it.

In order to be able to orient the container C, the orienting means 220 are disposed and/or configured to operate on the container C when the container C is in the lifted configuration, hence disengaged from the conveyor 100 (Figure 7). Preferably, the orienting means 220 comprise at least one motor-driven roller 221 (whose axis is, in particular, parallel to the orienting axis X) configured to engage the top of the container C and to make the container C rotate about the orienting axis X by a predetermined angle. Preferably, the orienting means 220 comprise two rollers 221 , disposed at the top of the container C and at least one of which is motor driven.

Thus, once it reaches the orienting device 200, the container C is initially supported by the conveyor 100 and then, after being lifted by the lift 21 1 , it is supported at the bottom by the rotatable support 212, at the top by the rollers 221 and at the sides by the guiding members 213.

Advantageously, the orienting device 200 also comprises at least one optical detector 230, specifically a photocell, directed towards the container C disposed on the conveyor 100 (at the lifted and/or lowered position) at the orienting device 200 to detect at least one mark or other visible reference spot on the container C. In particular, the optical detector 230, acting in conjunction with a control unit not illustrated, detects a mark (black, for example) or a change of colour on the container C, in particular, on a label previously applied to the container C. The angular position of the container C may thus be detected by means of a search algorithm run by the control unit which, based on the information received from the optical detector 230, identifies the exact angular position of the mark or change of colour. In an embodiment, detection by the optical detector 230, hence detecting the angular position of the container C, is carried out before or after lifting but in any case before the container C is set in rotation by the orienting means 220. In this embodiment, the container C is rotated about the orienting axis X by an angle determined by the control unit as a function of the angular position detected.

In a different embodiment, detection by the optical detector 230, hence detecting the angular position of the container C, is carried out while the container C is being rotated by the orienting means 220, for example, at predetermined intervals, and is preferable because the mark or change of colour might, at first, be outside the range of action of the optical detector 230. In this embodiment, therefore, once the mark or change of colour, hence the angular position of the container C, has been detected, the control unit may determine the angular amplitude through which the container C must still be rotated, or more preferably, detection of the mark or change of colour during rotation about the orienting axis X may itself be the condition indicating that alignment has been reached and the rotation of the container C is stopped at that instant.

Preferably, in order to reduce the amplitude of rotation of the container C about the orienting axis X, thereby accelerating the orienting process, at least two optical detectors 230 may be provided, angularly spaced from each other by an angle a of between 30° and 150°, for example, 60° or 120°, about the detection axis X. The angle a between the optical detector 230 can be varied for adjustment purposes, in particular by mounting at least one of the two detectors 230 on an arm 231 (preferably arcuate in shape) provided with an elongated adjustment slot 232.

Figures 2, 2A and 4 show different views of the applicator device 300.

The applicator device 300 is configured to apply at least one stamp B to each container C along an application direction transverse, preferably perpendicular, to the feed direction X. In the drawings, the application direction is vertical. The applicator device 300 may be schematically represented by the components shown in Figures 9A-9F: in particular, it comprises a pressing member 310 having a contact surface 31 1 , preferably concave, intended to come into shape fitting contact with each container C, a magazine 320 for holding a pile of stamps B and a pickup and transfer unit 330 interposed between the magazine 320 and the pressing member 310 to pick up a succession of stamps B from the magazine 320 and to release each stamp B next to a respective container C, at a position suitable for allowing the pressing member 310 to apply the stamp B to an outside surface, preferably convex, of the container C.

The pressing member 310 is associated with respective movement means (not illustrated) configured to impart to the pressing member 310 at least one movement component towards and away from the container C disposed at a stationary position at the applicator device 300. Preferably, the movement means comprise a lever or rocker mechanism or a linear actuator.

More in detail, the pickup and transfer unit 330 comprises a transfer wheel 331 that is movable, preferably with continuous, uniform motion, between a zone for receiving a stamp B (Figure 9C) and a zone for releasing the stamp B onto a container C (Figures 9E-9F). The transfer wheel 331 is externally provided with one or more retaining areas 332 for retaining respective stamps B, specifically by pneumatic suction. Further, the axis of rotation of the transfer wheel 331 is parallel to the feed direction X so as to transfer the stamps B tangentially to the containers C which have stopped at the applicator device 300.

The aforementioned release zone coincides with a movement zone of the pressing member 310 and an area immediately adjacent to the container C so that the pressing member 310 operates on a succession of stamps B released at the outside surface of the containers C by the transfer wheel 331.

The applicator device 300 also comprises a positioning member 340 acting in conjunction with the pressing member 310 to engage each stamp B while the stamp B is being applied on the respective container C by the pressing member 310 and, in particular, to detach the stamp B from the respective retaining area 332 of the transfer wheel so that the transfer wheel 331 can continue rotating while the stamp B remains in place adjacent to the container C. The positioning member 340 and the pressing member 310 are disposed and/or configured to engage the stamp B at different surface portions of the stamp B itself so that while the stamp B detached from the transfer wheel 331 by the positioning member 340 is held in place by the positioning member 340, the pressing member 310 can apply the stamp B by mechanically pressing it on the container C. Preferably, the positioning member 340 has a fork-like configuration to define a central passage intended for the movement of the pressing member 310 and/or of the transfer wheel 331 (in the embodiment illustrated, as shown in Figure 2A, it is the transfer wheel 331 that moves through the central passage of the positioning member 340, while the pressing member 310 is also fork shaped to operate on the outside of the positioning member 340).

Furthermore, as shown in Figures 9A-9F, the pickup and transfer unit 330 also comprises a pickup operating unit 333 interposed between the magazine 320 and the transfer wheel 331 and configured to pick up a succession of stamps B from the magazine 320 and to release each stamp B on a respective retaining area 332 of the transfer wheel 331 . The pickup operating unit 333 comprises a feed roller 334 and a reciprocating carriage 335 which moves along a direction tangential to the transfer wheel 331 and on which the feed roller 334 is rotatably mounted. The feed roller 334 and/or the carriage 335 are driven in such a way that the tangential speed of the feed roller 334 is substantially zero at an instant when a stamp B is picked up from the magazine 320 and substantially equal to the tangential speed of the transfer wheel 331 at an instant when the stamp B is released onto the transfer wheel 331. In other words, since the tangential speed of the feed roller 334 is given by a rotation contribution of the feed roller and a linear movement contribution of the carriage 335, the tangential speeds of the feed roller 334 at the two stamp B pickup and release positions of the feed roller 334 can be obtained by suitably checking the linear reciprocating movement of the carriage 335 and the rotation (preferably constant) of the feed roller 334.

Preferably, the applicator device 300 also comprises, along a feed path of the transfer wheel 331 between the receiving zone and the release zone, a gluer 350 configured to make one or more glue areas on the stamp B, and preferably also a scoring device (not illustrated) configured to make on the stamp B one or more lines of weakness intended to define programmed tear zones on the stamp B where the stamp is torn in a desired manner when the container C is opened. These lines of weakness are preferably disposed on the stamp B in such a way that when the stamp B is applied, they substantially coincide with the line joining the two half-shells of the container C.

Advantageously, the pressing member 310 is replaceable with at least one pressing member having a contact surface 311 with a different shape and/or a different size, in order to adapt the applicator device 300 to containers C of different formats and/or sizes. For example, the applicator device 300 may operate with a pressing member 310 whose shape contact surface 31 1 is concave, with an arcuate shape, and which may be replaced with an additional pressing member that is L-shaped to define an angular applicator for a container having the shape of a parallelepiped or V to apply a stamp to a lateral edge of a prismatic container with a hexagonal or octagonal base or to other types of containers. In effect, it is evident that the applicator can operate in exactly the same way with containers of different shapes by simply using a pressing member that is shaped to match the part of the container that is to receive the stamp.

Moreover, according to an inventive aspect of the invention, the applicator device 300 is adjustable along at least a first adjustment direction, transverse, preferably perpendicular, to the feed direction A, to adapt the applicator device 300 to containers of different formats and/or sizes instead of and/or in addition to replacing the pressing member 310.

Preferably, the first adjustment direction is also transverse, and more preferably, perpendicular, to the application direction, in particular horizontal (lateral with respect to the feed direction A).

In a preferred embodiment, the applicator device 300 is adjustable in at least two directions lying in a plane that is transverse, preferably perpendicular, to the feed direction A. Preferably, the two adjustment directions are horizontal (lateral) and vertical.

Moreover, in another embodiment, the applicator device 300 is adjustable in at least three adjustment directions: two directions lying in a plane that is transverse, preferably perpendicular, to the feed direction A (these two adjustment directions being horizontal and vertical) and a third direction that is transverse (preferably orthogonal) to the transverse plane.

To allow this adjustment to be made, the applicator device 300 is preferably mounted on an independent support 360, or "trestle", resting on the floor and provided with precision adjustment means (for example, a lead nut/screw mechanism) with precision graduated scales to make a precise adjustment in one, two or three directions.

According to another aspect of the invention, an additional pressing member 370 may be provided downstream of the applicator device 300 (or forming a part thereof) to press the stamp B on the respective container C at a position further downstream on the conveyor 100, after the stamp has been applied by the first pressing member 310. As shown in Figure 4, the pressing member 310 and the additional pressing member 370 may be rigidly connected in such a way as to be moved simultaneously by the same movement means.

Furthermore, in a possible embodiment, an inspection unit (not illustrated) is provided downstream of the applicator device 300, for example, an optical inspection unit, configured to detect that the stamp B is correctly positioned on the container C and, as a function of the detection performed, to determine whether the container C is conformant, hence directed to the outfeed section, or non-conformant, hence directed to the rejection section. In the former case, the container C reaches the outfeed station 3 where it is moved laterally away from the conveyor 100, for example by an expulsion belt device 400, provided with pushing teeth, and sent to an aligning block 500 provided with a twisted channel that can vary the orientation of the container, for example from vertical to horizontal.

In the latter case, on the other hand, the expulsion device 400 is not enabled and the container C remains on the conveyor 100, for example until it is discharged freely by gravity when the conveyor 100 changes direction or when it reaches another expulsion device (not illustrated).

The expulsion device 400 is thus enabled from time to time, as required, as a function of the signal generated for the respective container C by the inspection unit.

In use, a succession of containers C is fed to the conveyor 100, in the specific embodiment shown in the accompanying drawings by a front feed star wheel (Figure 3).

Next, the conveyor 100 (which is driven intermittently) transports each container C to the orienting device 200, where each container C is oriented about an orienting axis X, preferably parallel to the feed direction A of the conveyor 100, during an instant when the conveyor 100 stops, so as to dispose the containers C according to a predetermined angular orientation about the orienting axis X, suitable for a stamp B to be applied to each by the applicator device 300 that comes next.

The step of orienting the containers C is accomplished by temporarily disengaging each container C from the conveyor 100, and rotating the container C about the orienting axis X while the container C is disengaged from the conveyor 100, in particular, lifted by the lift 21 1 and rotated by the motor-driven rollers 221 .

The step of orienting the containers C also comprises a step of detecting at least one angular position of the container C, in particular an initial angular position and/or one or more angular positions adopted by the container C during its rotation about the orienting axis X. The step of rotating the container C about the orienting axis X is performed as a function of the at least one angular position detected. Detection of the angular position is accomplished by scanning the outside surface of the container C to identify the presence and position of a reference mark and/or one or more changes of colour or contrast.

Next, the containers C reach the applicator device 300, which applies at least one stamp B to each container C along an application direction transverse, preferably perpendicular, to the feed direction A, in particular vertical. The step of applying is carried out during an instant when the conveyor 100 stops.

The step of applying the stamp B to the container C is accomplished by pressing the stamp B on the container C by means of the concave contact surface 311 of the pressing member 310, configured to come into shape coupling contact with each of the containers C, and by moving the pressing member 310 at least along the application direction by means of the movement means until the contact surface 311 of the pressing member 310 makes solid contact with the outside surface of the container C and presses the stamp B onto the container C.

The step of applying the stamp B to the container C comprises a sub-step of picking up a stamp B from a pile of stamps disposed in the magazine 320 by means of a pickup and transfer unit 330 and a step of releasing each stamp B at a stationary position next to a respective container C by means of the pickup and transfer unit 330, at a position suitable for allowing the pressing member 310 to apply the stamp B to an outside surface of the container C.

More in detail, the step of applying the stamp B to the container C is accomplished through the following steps:

- placing the stamp B at or in proximity to the outside surface of the container C by a movement that is at least partly tangential to the container C, being, in particular, performed by the transfer wheel 331 by pneumatic suction applied to the retaining areas 332; next, stopping and holding the stamp B at a stationary position by means of the positioning member 340, which also detaches the stamp B from the transfer wheel 331 ; while the stamp B is being held at the stationary position by the positioning member 340, pressing the stamp B on the container C by means of the pressing member 310, where the pressing member 310 slides through the positioning member 340, which is fork shaped; where necessary, pressing the stamp B on the container C again using the additional pressing member 370.

More specifically, Figures 9A-9F show a succession of steps performed in the applicator device 300.

In step 9A, the carriage 335 moves with linear motion while the feed roller 334 rotates in the "opposite" direction, that is to say, in such a way that its tangential speed, confronting the magazine 320, is zero or substantially zero, so that the feed roller 334 can pick up a stationary stamp B from the pile of stamps (Figure 9B).

Preferably, since the transfer wheel 331 has two (or more) retaining areas 332, while the feed roller 334 picks up a stamp B from the magazine 320, the transfer wheel 331 places another stamp B, picked up previously, at the gluer 350 (Figure 9A) and/or at the scoring device. Between the step of picking up each stamp B from the pile of stamps in the magazine 320 and the step of releasing each stamp B next to a respective container C, there may, in effect, be a step of making one or more glue areas on the stamp B and preferably also a step of making on the stamp (B) one or more lines of weakness intended to define programmed tear zones on the stamp B where the stamp is torn in a desired manner when the container C is opened.

Next, where the feed roller 334, as it rotates, moves in the same direction, it releases the stamp B onto the next retaining area 332 on the transfer wheel 331 (Figure 9C). This is done while the peripheral, tangential speed of the feed roller 334 is substantially equal to that of the transfer wheel 331 , for example, when the carriage 335 slows down or stops (or while the carriage 335 continues in a uniform feed stretch).

In the next step, the carriage 335 starts moving back in the opposite direction to prepare to pick up the next stamp, while the previous stamp B reaches the container C it has to be applied to (Figure 9D). At the same time, or after that, the positioning member 340 detaches the stamp B from the retaining area 332 of the transfer wheel 331 and places the stamp B in contact with the outside surface of the container C (Figure 9E). The subsequent movement of the pressing member 310 causes the stamp B to adhere completely to the container C (Figure 9F).

Advantageously, the method also comprises a step of replacing the pressing member 310 with another pressing member having a contact surface with a different shape and/or a different size, in order to adapt the applicator device 300 to containers C of different formats and/or sizes.

According to an advantageous aspect of the invention, the method also comprises a step of adjusting the position of the applicator device 300 along at least a first adjustment direction that is transverse, preferably perpendicular, to the feed direction A in order to adapt the applicator device 300 to containers of different formats and/or sizes.

Preferably, the first adjustment direction is also transverse, preferably perpendicular, to the application direction.

In a preferred embodiment, the step of adjusting the position of the applicator device 300 is accomplished by adjusting the position of the applicator device 300 in at least two directions lying in a plane that is transverse, preferably perpendicular, to the feed direction A, in particular in a horizontal direction and a vertical direction. This allows very easily and effectively adjusting the position of the pressing member 310 relative to a container of different size and shape and/or varying the position where the stamp is applied to the container.

Figures 10 and 1 1 show an embodiment different from that described above, essentially in that it applies a stamp astride a lateral surface of a container C, the latter being preferably transported in such a way that it lies predominantly in a horizontal plane, hence with its top surface facing towards the pressing member 310.

In particular, as shown in Figures 10 and 1 1 , the container C is still supported by the conveyor 100, preferably a cleated conveyor, and once it enters the applicator device 300, it receives the stamp B from above in functionally the same way as in the preceding embodiment described above; in this case, however, the stamp B is not applied only to the top of the container C but is also pressed against the side of it. This is done, for example, by using a pressing member 310 that is L-shaped or has a concavity that is substantially shaped to match a corresponding outer profile of the container C. In the embodiment illustrated in Figure 10, the pressing member 310 is L-shaped and presses the stamp against two perpendicular surfaces of the container C. The pressing member 310 may move in translation in the vertical direction only (hence perpendicularly to the main upper surface of the container C) or it may move in an inclined direction so as to apply enough pressure to both the top and the side of the container, or it may have two degrees of freedom, for example, an initially vertical movement followed by a horizontal movement to press the stamp B against the side.

In this situation, however, the stamp B protrudes downwards from the container C.

In this case, application of the stamp B is completed by an auxiliary pressing member 312, disposed downstream of the pressing member 310 and is movable in a transverse direction, hence laterally and/or horizontally, to press the bottom flap of the stamp B against the underside surface of the container C. In this case, too, the pressing member 312 may move in translation in the vertical direction only (hence perpendicularly to the lateral surface of the container C) or it may move in an inclined direction so as to apply enough pressure to both the underside and the side of the container, or it may have two degrees of freedom, for example, an initially lateral movement followed by a vertical movement to press the stamp B against the underside.

To be able to perform this final pressing action, the conveyor 100 should preferably have lateral recesses or gaps to allow the auxiliary pressing member 312 to be inserted without interfering with the conveyor 100.

The invention described achieves the set aim by overcoming the disadvantages of the prior art.

The fact that the applicator device can be adjusted and the pressing member replaced allows the applicator device to be adapted to containers of different shapes and/or sizes and to stamps of different shapes and/or sizes.

Moreover, with the machine according to the invention, the stamp may be applied either tangentially, relative to a cylindrical outside surface of the containers, or transversely, hence transversely to the line joining the two half-shells of the container C. This may be achieved by orienting the containers so they are rotated by 90° about a vertical axis relative to the embodiment illustrated, or by rotating the applicator device.